PayPal Community

I have exactly the same problem! Payments work, only refunds do not. Kindly asking for a professional reply! Thanks in advance!  did check all the API-settings (and IPN) in the woocommerce plugin (called paypal standard), and still no change. We also tested from different locations (even countries) and computers. this is my log:  2021-04-08T11:39:57+00:00 INFO Received valid response from PayPal IPN 2021-04-08T11:39:57+00:00 INFO Found order #1322 2021-04-08T11:39:57+00:00 INFO Payment status: completed 2021-04-08T11:49:47+00:00 INFO Refund Response: Array ( [headers] => Requests_Utility_CaseInsensitiveDictionary Object ( [data:protected] => Array ( [content-type] => text/plain; charset=utf-8 [content-length] => 234 [date] => Thu, 08 Apr 2021 11:49:47 GMT [cache-control] => max-age=0, no-cache, no-store, must-revalidate [caller_acct_num] => (edited) [paypal-debug-id] => 1dcad1b492901 [x-paypal-api-rc] => 10002 [x-paypal-operation-name] => RefundTransaction [x-slr-retry-api] => RefundTransaction [http_x_pp_az_locator] => ccg13.slc [strict-transport-security] => max-age=31536000; includeSubDomains ) ) [body] => TIMESTAMP=2021%2d04%2d08T11%3a49%3a47Z&CORRELATIONID=1dcad1b492901&ACK=Failure&VERSION=84%2e0&BUILD=55475691&L_ERRORCODE0=10002&L_SHORTMESSAGE0=Security%20error&L_LONGMESSAGE0=Security%20header%20is%20not%20valid&L_SEVERITYCODE0=Error [response] => Array ( [code] => 200 [message] => OK ) [cookies] => Array ( ) [filename] => [http_response] => WP_HTTP_Requests_Response Object ( [response:protected] => Requests_Response Object ( [body] => TIMESTAMP=2021%2d04%2d08T11%3a49%3a47Z&CORRELATIONID=1dcad1b492901&ACK=Failure&VERSION=[Removed. Phone #s not permitted]AGE0=Security%20error&L_LONGMESSAGE0=Security%20header%20is%20not%20valid&L_SEVERITYCODE0=Error [raw] => HTTP/1.1 200 OK Content-Type: text/plain; charset=utf-8 Content-Length: 234 Connection: close Date: Thu, 08 Apr 2021 11:49:47 GMT Cache-Control: max-age=0, no-cache, no-store, must-revalidate Caller_acct_num: (edited) Paypal-Debug-Id: 1dcad1b492901 X-Paypal-Api-Rc: 10002 X-Paypal-Operation-Name: RefundTransaction X-Slr-Retry-Api: RefundTransaction HTTP_X_PP_AZ_LOCATOR: ccg13.slc Strict-Transport-Security: max-age=31536000; includeSubDomains TIMESTAMP=2021%2d04%2d08T11%3a49%3a47Z&CORRELATIONID=1dcad1b492901&ACK=Failure&VERSION=[Removed. Phone #s not permitted]AGE0=Security%20error&L_LONGMESSAGE0=Security%20header%20is%20not%20valid&L_SEVERITYCODE0=Error [headers] => Requests_Response_Headers Object ( [data:protected] => Array ( [content-type] => Array ( [0] => text/plain; charset=utf-8 ) [content-length] => Array ( [0] => 234 ) [date] => Array ( [0] => Thu, 08 Apr 2021 11:49:47 GMT ) [cache-control] => Array ( [0] => max-age=0, no-cache, no-store, must-revalidate ) [caller_acct_num] => Array ( [0] => (edited) ) [paypal-debug-id] => Array ( [0] => 1dcad1b492901 ) [x-paypal-api-rc] => Array ( [0] => 10002 ) [x-paypal-operation-name] => Array ( [0] => RefundTransaction ) [x-slr-retry-api] => Array ( [0] => RefundTransaction ) [http_x_pp_az_locator] => Array ( [0] => ccg13.slc ) [strict-transport-security] => Array ( [0] => max-age=31536000; includeSubDomains ) ) ) [status_code] => 200 [protocol_version] => 1.1 [success] => 1 [redirects] => 0 [url] => https://api-3t.paypal.com/nvp [history] => Array ( ) [cookies] => Requests_Cookie_Jar Object ( [cookies:protected] => Array ( ) ) ) [filename:protected] => [data] => [headers] => [status] => ) ) 2021-04-08T11:49:47+00:00 INFO Refund Result: stdClass Object ( [TIMESTAMP] => 2021-04-08T11:49:47Z [CORRELATIONID] => 1dcad1b492901 [ACK] => Failure [VERSION] => 84.0 [BUILD] => 55475691 [L_ERRORCODE0] => 10002 [L_SHORTMESSAGE0] => Security error [L_LONGMESSAGE0] => Security header is not valid [L_SEVERITYCODE0] => Error ) ... View more